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(No Model.) 2 Sheets-Sheet '1.

A. BITTER, Jr.,

STEAM BOILER FURNACE.

N0. Z90,270. Patented Dec. 18, 1883.

'ATTEST: 1' INVENTOR:

N, PETERS. Phowuflwgraphr, Walhingion. D. C.

(No Mpdel.)

2 Sheets-Sheet 2. A. BITTER, Jr.

STEAM BOILER FURNAGE.

Patented Dec. 18

FIG. 6'.

INVENTORI ATTESTI F QWL U N PETERS. Pimlwlilhngraphcr. Wamngmn. 0.6

llnrrn STATES PATENT Fries.

ANDRE? BITTER, JR, OF CHICAGO, ILLINOIS, ASSIGNOR OF TWO-THIRDS TO A. F. NOBLE AND JAMES C. POLLOCK, BOTH OF SAME PLACE.

STEAM-BOILER FURNACE.

SPECIFICATION forming part of Letters Patent No. 290,270, dated December 18, 1883.

Application filed September 3, 1883. (No model.)

To aZZ whom it may concern.-

Be it known that I, ANDREW BITTER, J r.,

a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Steam-Boiler and other Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to improvements that are more especially adapted to that class of furnaces in which the fire-chamber is arranged at either the front or side of the boiler or other chamber in order to permit of the readyand convenient feeding of the same through openings in the arch of the fire-chamber, and to attain a more perfect combustion of the fuel and my improvement has for its objects, first, to provide means for heating the airsupply and distributing it in an even manner through the fire-chamber, so as to aid in the thorough and perfect combustion of the gaseous products of the fuel; second, to afford means to prevent excessive radiation of heat from the furnace into the furnace-room, and at the same timeutilize the heat which would otherwise be lost by radiation to 'heat a sup ply of air used to assist in promoting the combustion of the fuel; third, to furnish an improved construction whereby the fuel can be readily and conveniently fed to the furnace, the escape of smoke and gases into the room prevented, and the draft, to a measure, promoted and regulated. I attain such objects by the construction and arrangement of parts illustrated in the accompanying drawings, in 'which- Figure 1 is a longitudinal section of a hori zontal steam-boiler furnace to which my improvements are applied ,Fig. 2, a front elevation of the same, partly in section; Fig. 3, an enlarged horizontal section through the arch of the furnace-chamber; Fig. 4, an enlarged detail View of the grates, and Fig. 5 an enlarged detail View of the hinged drop-plate at the rear of the furnace-grate.

The furnace, as usually constructed, consists of a fire-chamber, A, having a central horizontal grate, B, and inclined side grate, C, on which the fuel is fed through feed pockets or chutes D in the arched top E of the furnace.

, In order to feed the fuel down onto the central grate, B, from the inclined grates C, Y I form such grates so that they will oscillate or rock. My preferred form of rocking grate for this purpose is shown in Fig. 5, yet any other style of rocking grate may be employed 6@ without departing from the spirit of my invention. By this means the fuel can be evenly and perfectly fed down onto the central grate without necessitating stoking of the fire through the ordinary front fire-door of the furnace.

F is the front plate of the furnace, arranged at a short distance from the furnacewall proper, so as to form an air chamber or space, as shown','the purpose of this construction bemg to prevent radiation of heat from the furnace-wall into the furnace-room by causing a circulation of air in the space or chamber, the air-supply being taken in through openings f and discharged into the fire-chamber, to promote combustion, through the flues or passages G G, in the furnace-arch, as shown in Figs. land 8. The horizontal fines or passages G are of varying lengths, and discharge at different points into the furnace-chamber, so through short downwardly-inclined ducts or passages, so as to furnish an even supply of air to all parts of the same, and thereby effect a more perfect combustion of the gaseous products of the fuel. A portion, G, of the $5 horizontal fiues G do not communicate with the air-heating chamber 'at the front of the firechamber, but take their supply of air from over the arch, through upwardly inclined ducts or passages 9, so as to take air from 0 such point and absorb most of the heat radiated therefrom.

(Z are vertical air-feeding flues or apertures formed in the division between the feeding pockets or chutes, the purpose of which is to 9 5 carry a supply of air into the fire-chamber whenthe supply ofair through the pockets D is interfered with or prevented by the fill-- ing up of the same with small fuel.

H are air supplying and heating fines or pas- Ioo sages formed in the side walls of the furnace,

which take their supply ofair through the front of the furnace and discharge it through small cross fines or passages into the fuel-pockets D. By means of the fines d and H, a sufficient sup ply of air is furnished to the fire-chamber, so that there will be no necessity of an air-supply through the pockets, and consequently the doors or covers (1 of the same can be kept closed at all times, except when feeding fuel into the pockets. By this means anyliability of smoke or gases escaping into the furnaceroom is entirely overcome. This construction has the further advantage of preventing any undue heating of the doors or covers 01, and the consequent warping and cracking of the same, and is especially valuable where the furnace is lightly fired, as it obviates the necessity'of using the doors (2 to regulate the draft.

In practical use the various air-supplying fines or passages will be provided with regulating dampers or stoppers, so as to enable the operator to control the supply of air to the furnace or any desired portion of the same. It is preferred that any retarding of the draft be accomplished bya damper, J, in the breeching or smoke-stack of the boiler.

I is a removable metal arch-plate placed over the furnace-arch, the purpose of which is twofold: first, to form a con-conducting airspace over the furnace-arch; and, second, to form, when turned upside down, a protectingtrough for the top of the furnace in clearing out or washing the boiler.

\Vith the improved furnace, as shown, there is a double draft through the furnace, which at times tends to cause a backing up of the heat against the ends of the inclined grates, causing them to unduly expand and buckle up. I have found by practical experience that this defect can be almost entirely obviated by cutting out or forming an offset, 0, in the side walls underneath the grates, as clearly indicated in Fig. 2.

K is a perforated drop-plate hinged in the bearing-bars of the central grate and arranged directly behind the same, the purpose of which is to permit of the cleaning of the fire through the rear of the furnace, toward which the clinkers naturally form, and in the removal of which, by the means stated, does not require the green coal at the front of the furnace to be disturbed, as would be the ease in cleaning in the usual way through the front door of the furnace. The drop-plate is manipulated by means of a lever, is, at the front of the furnace, although the connecting-rod k, extends to the arm of the drop-plate, as clearly indicated in Figs. 2 and .3.

XVhile it is preferable to arrange the fur nace or fire chamber directly in front of the boiler and longitudinally parallel therewith,

yet in some cases it may be more convenient to place it at the side of the boiler, or at an angle thereto, or, if absolutely necessary, directly under the boiler, either of which arrangements, as found most convenient or necessary, may be employed without departing from the spirit of my invention.

In the drawings I have shown the central grate as being capable of a rocking motion, so as to clear the fire by rocking the same; yet the ordinary fixed grate-bar may be employed instead, and the usual mode of cleaning the fire by poking the same may be resorted to.

I am aware that prior to my invention furnaces have had their walls formed with airheating ducts or passages for heating a supply of air to promote combustion. I therefore do not claim such provision, broadly.

I am also aware that the front walls and furnace arch or top have been formed with passages or chambers to prevent the radiation of heat from the furnace, and that the arched top of furnaces have been provided with a fixed arch plate or cover of metal, to protect the same and to form an air-chamber to prevent radiation.

hatI do claim as my invention, anddesire to secure by Letters Patent, is

1. In a steam-boiler furnace, the fire-chamber A, having an arched top and provided with a central grate, B, inclined side grates, O, and side fuel-feeding pockets, D, in combibination with the air-heating passages H, discharging into the fuel-pockets, as described, and for the purpose set forth.

2. In a boiler-furnace, the fire-chamber A, having an arched top and provided with a central grate, B, inclined side grates, C, and side fuel-feeding pockets, D, in combination with the vertical air-supply flue (1, formed in the partition between the pockets D, as described, and for the purpose set forth.

3. In a boiler-furnace, the fire-chamber A, having an arched top and provided with a central grate, B, inclined side grates, C, and side fuel-feeding pockets, D, in combination with the air-heating passages I-I, formed in the furnace side walls, and vertical fine or passage (l, as described, and for the purpose set forth.

4. In a boiler-furnace, the fire-chamber A, having an arched top, fire-grates B O, and fuel-feeding pockets D, in combination with air-heating passages G, of varying lengths, formed in the furnace-arch and discharging through short ducts down into the fire-chamber, as described, and for the purpose set forth.

5. In a furnace, the combination of the following elements: the air space or passage formed in front of the front wall of the furnace by plate F, and the horizontal heatingflues G, communicating with said air space or passage and the interior of the fire-chamber, as described, and for the purpose set forth.

6. The combination,with a furnace, of a series of horizontalheating-flues, G G, formed in the arch of the fire-chamber and having openings into the fire-chamber over the fuel, the supply of air being taken, respectively, from the chamber in front of the furnace and from the top of the furnace through small ducts 9, substantially as described, and for the purpose set forth.

7. The c01nbinatio11,With a steam-boiler furnace in which the fire-chamber is arranged to the front of the boiler, of the curved plate I, arranged to form an air-conduit, and made removable and adapted to be reversed to form a receiving-trough, to protect the top of the fire-chamber in cleaning the boiler, all essentially as herein described.

8. The combination, in a boiler-furnace, of the fuel-feeding pockets D, inclined side grates, O 0, horizontal central grate, B, and drop -plate or grate K, arranged at the rear of the grate 15 B, as described, and for the purpose set forth.

In testimony whereof I have hereunto set my hand this 30th day of August, A. D. 1883.

' ANDREW BITTER, J R.

In presence of- A. F. NOBLE, I H. D. SMALLEY. 

